Field of the Invention
The present invention relates to automatic irrigation with humidity sensors, and more specifically to a system and method for more efficient automatic irrigation based on a large number of cheap humidity sensors and cheap automatic faucets, which can optimize the use of water so that less water is wasted and each plant or group of plants can get the optimal amount of water that it needs. Various solutions shown in the patent can be used for example for gardens, agriculture, and flowerpots (for example at homes or in plant nurseries).
Background
The most efficient water irrigation systems today for gardens and/or fields typically use dripping systems that release drops of water at certain distance intervals for example for about 30-60 minutes per day (for example every 30-100 cm of the pipe there is dropper that releases typically 2 litters of water per hour) and are typically controlled by timers that start or stop the water in the main pipes. However, although this is in general more efficient than systems that do not use droppers, this can still be far from optimal since it does not take into account different needs for each area, depending for example on the individual needs of each plant, heterogeneity of soil type, different amount of Sun or shade in each part of the garden or field, different number of plants in each area, etc. In other words, irrigation systems based on pipes with droppers, typically controlled only with a timer, which are the most common form of irrigation used today, suffer from one very basic weakness, which is that they have no feedback, so they are in essence working blindly. Another problem, which is related to the above lack of feedback, is that there is no efficient way of self-monitoring, so typically, since the system is not aware of its own condition, it also cannot report problems, such as for example breach of main pipes that can cause flooding, or, in the other direction, various pipes or side-channels becoming blocked. Therefore, these systems typically can still waste a lot of water on the one hand and neglect many plants on the other hand, so that some plants get too much water and others get too little water. For example, a raspberry plant or a weeping willow tree typically needs much more water than other plants. Similarly, to the best of our knowledge, there is no simple solution for efficient cheap automatic irrigation of plants in multiple flowerpots that can be used easily with ordinary flowerpots, for example in homes and in plant nurseries that sell plants, except for inserting a pipe in each flowerpot and opening and closing large groups of them by time control, which suffers from all the drawbacks described above. British patent 2281182 describes a closed container of water covered with a capillary mat on its top on which flowerpots are placed. However, this can reduce the efficiency of water uptake compared to placing the flowerpots directly in a water-filled bottom dish, and also the container is filled manually. Many patents describe the use of a water container coupled to a flowerpot that automatically lets the flowerpot draw water when needed, but only few of them, such as U.S. Pat. Nos. 5,918,415, 4,083,147, 4,546,571, and 4,557,071 describe a truly automatic refilling of the container. However, even those typically use a complex configuration that can't be used with normal flowerpots or requires a complex control valve. Anyway, in practice in homes and even in many plant nurseries the plants are still typically watered manually. Therefore, many plants either get too much water, or are neglected and dry out.
Saving water is very important, since according to the World Watch 2000 report we are depleting the planet's water resources at the rate of 109 billion gallons of water per day. Many areas in the world already suffer shortages of water, and others will suffer from it in the coming years. Israel, for example, is now in a critical stage of water shortage, with the Kineret sea's water level already at a critically low level. Therefore, in addition to more desalination of water, more efficient irrigation systems are essential for our survival on this planet.
In order to improve the efficiency of the automatic irrigation systems, humidity sensors are needed, however, although many types of humidity sensors exist, they are typically quite expensive (typically between $150 to even thousands of dollars), and automatic faucets are also typically relatively expensive (costing typically at least a few dozens of dollars each, since they typically contain an electric motor, good insulation between the water and the electrical parts, etc.), so they are not used for controlling more optimally the amount of water for each individual plant or for each small group of plants or small area. Also, many of the known methods for humidity sensing suffer from various limitations, such as for example limited range of response, sensitivity to changes in the salinity of the ground, sensitivity to changes in temperature of the ground, etc. So clearly cheaper good sensors and cheaper automatic valves are needed. Such a cheap solution would also be very attractive to customers and encourage them to use it, since a cheap enough system that saves a lot of money on watering per month while also improving plant growth, can preferably pay itself back in a few months or even less and start actually saving money for the customer.